Mounting for roof top air conditioner

ABSTRACT

A RECTILINEAR UPSTANDING, CONTINUOUS, RIGID CURB ON A FLAT ROOF TOP DEFINES AN OPENING THROUGH THE ROOF. VIBRATION ISOLATION MEANS ARE SUPPORTED ON TOP OF THE PERIPHERY OF THIS CURB AND, IN TURN, SUPPORT THE MAIN FRAME OF A COMPLETE AIR CONDITIONING UNIT. THE VIBRATION ISOLATION MEANS INCLUDES A CONTINUOUS SHEET OF FLEXIBLE MATERIAL IN SEALING RELATIONSHIP TO BOTH THE ENTIRE LOWER OUTER PERIPHERY OF THE AIR CONDITIONING UNIT FRAME AND THE ENTIRE UPPER OUTER PERIPHERY OF THE CURB, AND LOOSELY DIPOSED BETWEEN THE CURB AND FRAME. THIS SHEET ISOLATES THE INSIDE OF THE AIR CONDITIONING UNIT AND BUILDING FROM THE OUTSIDE THEREOF, AND INSULATES THE SPACE WITHIN THE CURB AND THE UNIT FROM THE TEMPERATURE AND WEATHER CONDITIONS OUTSIDE.

H. c. BIERWIRTH ETAL 3,721,106

MOUNTING FOR ROOF TOP AIR CONDITIONER March 20, 1973 2 Sheets-Sheet 1Filed Aug. 18, 1971 m I U V vN I MalCh 20, 1973 H RTH ET AL 3,721,)6

MOUNTING FOR ROOF TOP AIR CONDITIONER Filed Aug. 18, 1971 2 Sheets-Sheet2 IN VENTORS HEA/Ry C. .B/ERhl/PT J4 MES 1 F0 7) 4 rramm'r:

United States Patent O 3,721,106 MOUNTING FOR ROOF TOP AIR CONDITEONERHenry C. Bierwirth, Wayzata, and James V. Foty, Minneapolis, Minm,assignors to Lear Siegler, Inc., Minneapolis, Minn.

Filed Aug. 18, 1971, Ser. No. 172,779 Int. Cl. F25d 19/00 U.S. Cl.62-297 4 Claims ABSTRACT OF THE DTSCLOSURE A rectilinear upstanding,continuous, rigid curb on a flat roof top defines an opening through theroof. Vibration isolation means are supported on top of the periphery ofthis curb and, in turn, support the main frame of a complete airconditioning unit. The vibration isolation means includes a continuoussheet of flexible material in sealing relationship to both the entirelower outer periphery of the air conditioning unit frame and the entireupper outer periphery of the curb, and loosely disposed between the curband frame. This sheet isolates the inside of the air conditioning unitand building from the outside thereof; and insulates the space Withinthe curb and the unit from the temperature and weather conditionsoutside.

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This invention relates to the mounting of complete air conditioningpackages on building roof tops in such a manner as to insulate the roofand the remainder of the building from the audible and other vibrationsnaturally set up within the air conditioning package during normaloperation thereof.

Increasingly it has become desirable to mount complete air conditioningunits on the top of fiat-roofed industrial, commercial and institutionalbuildings. Customarily this has been done in the past by completing thetop roof of the building, providing a special charatcer roofing in thearea where the air conditioning unit is to be set, and then building upthe air conditioning package on the roof top. An overall housing orcover is provided for the unit, and the air ducts work and power energyconduits are connected between the unit and the interior of the buildingthrough the roof.

A considerable amount of vibration is associated with the operation ofthe motors, fans, compressors and the like of a roof top airconditioning unit, and the transmission of noise and other vibrationsfrom the unit to the interior of the building poses a severe problem.For example, where areas in the interior of the building immediatelyadjacent to the roof are designed for such uses as classroom instructionor the like, arbitrary restrictions are placed on the location of theair conditioning unit on the roof top often at the sacrifice of a gooddesign practice occasioned by losses in operating efiiciency andincluding increases in installation and operating expense.

Attempts have been made to isolate the individual pieces of theequipment causing the vibration problems by mounting such units onsprings or resilient cushions or the like, but such attempts have provedprohibitively costly and/or substantially ineffective to eliminate theunwanted vibrations.

Other methods of accomplishing vibration isolation include thesupporting of the entire air conditioning package on steel rails whichare in turn supported on the roof. A plurality of vibration isolationpads are then mounted between the air conditioning unit and the rails.This structure is unduly costly and raises the unit height to anunacceptable level. Also, this system requires special roofing under therails, and requires a considerable amount of field labor. The vibrationisolation pads are subject to weathering and wear from temperaturechanges because they must stand in the weather. Noises generated withinthe unit are transmitted into the building using the roof as a soundingboard.

It is known to mount ventilating and air conditioning apparatus in anopening in a roof top. See FIG. 3 of U.S. Pat. No. 2,134,142, and U.S.Pat. No. 2,882,810, for example.

Mounting equipment on a floor or root and to attempt to isolate thatequipment from the floor or roof by vibration isolation units is seen inU.S. Pats. Nos. 1,066,209; 2,359,941; and 1,089,748.

It is known to use a pad of resilient material between the top of a curbor wall and transparent skylight panels. See U.S. Pat, No. 3,405,487.

Before the present invention, however, no structure has been shown orsuggested by the prior art which will permit the installation of an airconditioning unit on the roof of a building at any desired location,will isolate the interior of the building from the vibrations created inthe air conditioning unit, and simultaneously isolate and insulate theinteriors of the building, the air conditioning unit, and the vibrationisolation means from weather conditions outside the building.

BRIEF SUMMARY OF THE INVENTION The fiat roof of a building designed toaccommodate a rooftop air conditioning unit is provided with a rigid,upstanding curb which defines an opening through the roof in underlyingrelationship to the chosen location of the air conditioning unit. Theair conditioning unit consists of a complete package mounted on aunitary horizontal main air conditioning unit frame. A plurality ofvibration isolation stantions are supported on the upper edge of thecurb and, in turn, support the lower edge of the unitary airconditioning unit frame. A continuous, loosely disposed layer ofmaterial is situated in sealing relationship to the entire upperperiphery of the curb and the entire lower periphery of the airconditioning frame. Separate means, forming no part of the invention,are to be provided to isolate against vibrations, the air supply andreturn ducts and the gas, electrical, and/or other energy and controlconduits extending through the roof opening to the interior of thebuilding.

IN THE DRAWINGS FIG. 1 is a fragmentary top plan view of a fiat roof-topand of a roof-top air conditioning unit mounted thereon;

FIG. 2 is an enlarged, fragmentary vertical sectional view of theportion of the air conditioning unit and rooftop taken on the line 22 inFIG. 1;

FIG. 3 is a further enlarged fragmentary view also taken substantiallyon the line 2-2 in FIG. 1, and showing further details of a specificvibration isolation structure between the air conditioning unit frameand the curb; and

FIG. 4 is a horizontal sectional view taken on the line 4-4 in FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENT In the form of the invention asshown, a complete air conditioning unit package 10 includes an outercasing 12, an air conditioner 14, air ducts including intake air duct16, intake and discharge louvers 13, conditioned air supply and returnducts 2-0, and electrical, gas, and/or other energy and control linessuch as that represented by energy and control cable 22. The makeup ofthe particular packaged air conditioning unit is not imp rtant to theprinciple of ti is invention per se, except that each such unit developssound and other unwanted vibrations. A packaged air conditioning unit ofthe invention will be mounted upon and will include a continuous mainair conditioning unit frame 24, having a continuous outer periphery, theouter casing 12 of the air conditioning unit being in sealingrelationship to this entire outer periphery of the main frame 24-.Appropriate layers of insulating material 26 are associated with theouter casing 12 of the package to provide vibration and temperatureinsulation between the outside and the inside of the unit outer casing12.

A building 28 on which the packaged air conditioning unit It isinstalled includes a flat-top roof 30 on which a rectilinear,upstanding, continuous rigid curb 32 is mounted to define an opening 34through the roof.

As shown, a metal flashing 36 extends from the roof, and up the outsidesurface of the curb. This flashing has an upper edge portion 38 whichinitially extends out- Wardly from the top of the curb (as seen indotted lines) and which can be deformed downwardly for a purpose to bedescribed, as seen in full lines.

The vibration isolation means 40, as shown, includes a resilientcontinuous pad 42 which extends in sealing relation to the entireperiphery of a bottom support surface 41 of the main air conditioningunit frame 24. A continuous inverted channel member 44 provides an uppersurface 45 in contact with the pad 42, and is provided with an initiallyoutwardly positioned flange 46 (illustrated in dotted lines), which canbe deformed inwardly during the installation of the unit and thevibration isolation means for a purpose to be described and to positionas illustrated in full lines.

The channel member 44 and the pad 42 are supported with respect to thecurb 32 by a plurality of vibration isolation stantions 48. It is to beunderstood that these stantions will be spaced sufficiently close toeach other to easily bear the weight of the air conditioning unit andthat the channel members 44 will be sufficiently rigid so that thestantions will support this channel member and the pad 42 in sealingrelationship with each other and with the bottom support surface 41 ofthe main frame 26 of the air conditioning unit.

While a particular form of vibration isolation stantion or uprightisolation device is shown, it is to be understood that such a devicecould take any one of a number of different forms and still come Withinthe concept of the invention. As shown, then, each stantion includes aresilient, disc-like footing member 56 supported on the curb 32; anelongated slotted plate 52 having a central portion of size and shape tocompletely overlie the footing member four arcuate, parallel verticallegs integral with and extending upwardly from the upper surface of theplate 52, two of such legs being at each end of the elongated plate; anda compression coil spring 56 resting on plate 52 inside the spacedefined by the upwardly extending legs 54.

On this curb-supported, upwardly extending assembly is placed a rigidhead member 58 which includes a support plate 60, a downwardly extendinghead shaft 62 integral with the support plate '60, two parallel,downwardly extending, arcuate legs 64 also integral with the plate 60and a spring support collar 66 extending integrally outwardly from shaft62 and of configuration to lie within the space provided by the arcuatelegs 54 and 64 to be in bearing relationship to the top of thecompression coil spring 56.

In order to fixedly position the stantions 43, bolts 63 are provided tofit into the slotted openings of the plates 52. As best seen in FIG. 3,these bolts can be anchored in the curb in any convenient or preferredmanner.

When the stantions have been fixed in their preferred locations, theinverted channel member 44 is then put in place to come into bearingrelationship with each of the upper support plates 6% of the stantions48, and the continuous resilient pad 42 is placed on top of the channelmember.

Next, a continuous sheet of flexible material 70 will be positionedaround the entire outer periphery of the vibration isolation means. Anupper edge portion 72 thereof will be placed between the flange 46 andits adjacent leg of the inverted channel member 44, and the flange willbe forced back on the edge portion 72 to fixedly clamp it in sealingrelation to the entire periphery of the channel member 44. A lower edgeportion 44 of the continuous sheet of flexible material 70- willlikewise be positioned between the edge portion 38 of the flashing 36,and this portion 38 will be forced back against the flashing 36 tofixedly position the lower edge portion 74 of the material in sealingrelation with the entire upper outer edge portion of the curb 32.

Many kinds of flexible materials will be satisfactory in structure inaccordance with the invention. Such material can be made of rubber,plastic, or woven fibrous material, or metallic bellows-shaped stripshaving flutes that run longitudinally around the curb. Laminates ofseveral materials can also be used. The material is disposed looselybetween the curb and the unit frame. The attributes for the flexiblematerial include inability to transmit vibration from the upper edgeportion to the lower edge portion thereof and ability to prevent anywind from passing therethrough. Other desirable attributes can includesound-deadening properties and/or temperature insulation properties.

When the vibration isolation means has been 'built up as describedabove, the air conditioning unit main frame 24 can be lowered intoposition so that the bottom support surface thereof comes into sealingrelationship with the continuous resilient pad 42. This can be done bylowering the entire package unit into place at once, or the main framecan be positioned first and then the conditioning unit built up thereon.

Means forming no part of the present invention will be provided toisolate against transmissions of vibrations along energy and controlcables such as 22 or conduits and along conditioned air ducts such asillustrated at 20.

When the air conditioning unit is put into operation, the verticalcomponents of the vibration will be absorbed by the compression coilspring 56 as the metallic head member 58 vibrates harmlessly andnoiselessly up and down with respect to the footing member 50. Thehorizontal components of vibration tend to be absorbed by the resilientpad 42 and cannot be transmitted between the head member 58 and theslotted plate 52 because there is no direct contact between them.

Because the flexible material 70 prevents the ambient weather conditionsfrom having any effect beneath the surface of the suspended airconditioning unit, there is no need for a roof under the unit, and theexpense of such construction is eliminated. Also eliminated, therefore,is the need for special roofing under the air conditioning unit as hasbeen necessary when the units of the prior art have been set on roofsurfaces which can no longer be properly maintained, repaired andreplaced without moving the entire air conditioning unit. The stantionsthemselves will not deteriorate either because they are also out of theweather. The only field installation necessary after the roof, curb andstantions have been prepared is the crimping of the flange 46 and theupper edge portion 38 of the flashing 36 on the upper and lower portionsof the flexible material 70, respectively; and the lowering of the airconditioning packaged unit into place.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:

1. A structure for mounting an air conditioning unit having a unitarymain frame which provides a continous peripheral support surface, saidstructure including:

(a) a flat roof surface;

(b) a rigid continuous curb extending upwardly from said flat rootsurface and defining an opening in the roof;

(c) a vibration isolation support supported with respect to said curbaround the periphery of the roof opening and supporting said main airconditioning unit frame; and

(d) a continuous sheet of flexible material extending loosely betweensaid air conditioning unit and said curb, said material being in sealingrelation with the bottom periphery of said air conditioning unit andwith the upper periphery of said curb and isolating the inside of saidbuilding and unit from the outside thereof.

2. The combination of claim 1 wherein the curb is rectilinear inconfiguration, and the roof top and the curb top each lie in spacedapart horizontal planes; and the main frame of the air conditioning unitis of configuration to overlie and slightly overhang the vibrationisolation support when the support is supported with respect to thecurb.

3. The combination of claim 1 wherein the vibration isolation supportincludes a plurality of vibration isolation stantions in which an uppermain frame supporting member is isolated from a lower curb supportedmember by upright resilient means capable of reciprocating verticalmovement in response to the vertical components of vibrations in saidunit.

4. The combination of claim 3 wherein said upright resilient means is acoil spring located in load bearing relation to said upper and lowermembers.

References Cited UNITED STATES PATENTS 15 WILLIAM J. WYE, PrimaryExaminer US. Cl. X.R. 62295; 259

